1. Field of the Invention
The present invention relates to a bobbin fixing apparatus, and more particularly, to a bobbin fixing apparatus in which a bobbin is placed on a rotating shaft to ensure simplified coupling/separation and normal rotation thereof regardless of a direction in which the bobbin is placed on the rotating shaft, and an end of an object to be wound on or unwound from the bobbin can be kept in a fixed position or released from the fixed position when the bobbin is placed on the rotating shaft, resulting in increased fixing convenience.
2. Description of the Related Art
In general, a bobbin is a device around which an extremely long slender object is wound for storage or unwound for use. The bobbin is secured to a rotating shaft such that the object is wound on or unwound from the bobbin via rotation of the bobbin.
Referring to FIG. 7, a conventional bobbin fixing apparatus includes a rotating shaft 2 rotatably installed to a mounting plate 5 such that a bobbin B is placed on the rotating shaft 2.
The conventional bobbin fixing apparatus is provided at an end of the rotating shaft 2 with a detent 1 to prevent separation of the bobbin B placed on the rotating shaft 2. To this end, the detent 1 is adapted to be rotated when the bobbin B is placed on the rotating shaft 2. In addition, an elastic spring (not shown) and a horizontally movable stopper (not shown) are accommodated in the rotating shaft 2, and a lower end of a hinge 3 is connected to a central position of the rotating shaft 2.
A detent insertion recess 7 is indented in an outer surface of the bobbin B. When the detent 1 is rotated, a part of the detent 1 is inserted into the detent insertion recess 7 to allow the bobbin B to be secured to the rotating shaft 2.
With the use of the bobbin fixing apparatus having the above described configuration, if the bobbin B is placed on the rotating shaft 2, the hinge 3 comes into contact with an inner surface of the bobbin B and is pushed into the rotating shaft 2 upon receiving pressure applied by the bobbin B. In this case, the stopper and the elastic spring assist in pushing the hinge 3 into the rotating shaft 2, thereby causing the detent 1 to be rotated and inserted into the detent insertion recess 7 in linkage with movement of the hinge 3. As such, the bobbin B is secured to the rotating shaft 2.
Additionally, referring to FIG. 8, a coupling member 9a, by which an end of an object to be wound is caught, is installed on the bobbin B. A rotatable member 9b is rotatably seated on an upper surface of the coupling member 9a using an elastic torsion member (not shown) to keep the end of the object in a fixed position.
To keep the end of the object in a fixed position prior to winding the object on the bobbin B, it is necessary for an operator to press one side of the rotatable member 9b so as to lift the rotatable member 9b. Then, as the user releases the rotatable member 9b after putting the end of the object into the coupling member 9a, the end of the object is kept in a fixed position.
In the case of the above described conventional bobbin fixing apparatus, however, since the detent 1 is rotated and inserted into the detent insertion recess 7 to secure the bobbin B to the rotating shaft 2 when the bobbin B is placed on the rotating shaft 2, replacement of the bobbin B is troublesome because it is necessary to forcibly rotate the detent 1 inserted in the detent insertion recess 7 in order to separate the bobbin B from the rotating shaft 2.
In particular, although the bobbin B may act to push the hinge 3 thus causing rotation of the detent 1 even if the bobbin B is incorrectly placed, the detent 1 may fail to accurately secure the incorrectly positioned bobbin B.
If the rotating shaft 2 is rotated in a state in which the bobbin B is not accurately secured, the bobbin B may be unintentionally separated from the rotating shaft 2 during rotation of the rotating shaft 2, which may stop a current operation and cause damage to a device, to which the bobbin B is installed, or damage to an object wound on the bobbin B.
In addition, since putting or taking the end of the object into or from the coupling member 9a requires for the operator to press the rotatable member 9b, unwinding the object from the bobbin B requires a troublesome process in that the operator must temporarily stop an unwinding operation to press the rotatable member 9b and then, restart the unwinding operation after taking the end of the object from the coupling member 9a. 
In particular, if the rotating shaft 2 is rotated before the end of the object wound on the bobbin B is not yet released from the fixed position, this may cause damage to the object.